1. Field of the Invention
The present invention relates to an X-ray diagnosis apparatus using a C-arm type holding device for holding an X-ray source and a detector for detecting X-ray, which face each other, and more particularly, to an X-ray diagnosis apparatus including a driving mechanism for forwardly or backwardly moving a detector relative to an object to be detected, which lies on a top board of a bed.
2. Description of the Related Art
In a clinical field, an X-ray diagnosis apparatus using a C-arm type holding device for holding an X-ray source and a detector for detecting X-ray, which face each other across an object to be detected (patient) on a top board, is known (Japanese Unexamined Patent Application Publication No. 2004-357987). An example of the X-ray diagnosis apparatus is shown in FIGS. 1 and 2.
The X-ray diagnosis apparatus 100 shown in FIG. 1 includes a top board (bed) 101 on which an object to be detected P lies, a C-arm (holding device) 1 for holding an X-ray tube 4 (X-ray source) including an X-ray diaphragm on one side of an object to be detected on the top board 101, and a detector 2 as an image receiving system on the other side thereof, a pedestal (not shown) for movably holding the top board 101 and the C-arm 1, and various operating consoles (not shown) for X-ray photographing.
The X-ray diagnosis apparatus 100 can clinically perform various operations including erection, elevation, forward and backward movement, and left and right movement of the top board 101 relative to the pedestal, longitudinal movement, rotation, and arc movement of the c-arm 1 relative to the pedestal, and forward and backward movement of the detector 1 relative to the top board 101, in order to variously perform necessary positioning.
Among them, as shown in FIG. 2, there is known driving means (driving unit) which forwardly and backwardly moves the detector 2 to and from the object to be detected on the top board 101 relative to the C-arm 1 and drives the detector 2 attached to a belt by a mechanism in which the belt is stretched over a pair of pulley (driving pulley and driven pulley) in a loop shape or a detector 2 attached to a rack by a mechanism using the rack and a pinion.
This mechanism includes a motor 3101 in a first frame 31, a pair of pulleys 3102 and 3102, and a belt 3103 stretched over the pair of pulleys 3102. The motor 3101 is connected to one of the pair of pulleys 3102, and a second frame 32 is connected to the belt 3103 by a connection member 50 such that the detector 2 held by the second frame 32 can move toward the object to be detected P.
However, in the driving means (driving unit 3) employing a one-step slide mechanism using two frames, since the length of the driving unit 3 cannot freely extend by limit of a mounting space, it is difficult to ensure a large movement range of the detector 2.
In other words, when the movement range of the detector is lengthened, the mounting space need become wider and an interval between the X-ray source and the detector becomes narrower. Accordingly, a space for setting the object to be detected (patient) on a photographing position becomes narrower and thus a layout having a difficulty in use is obtained. In contrast, when the interval between the X-ray source and the detector becomes wider, the movement range of the detector becomes narrower and a freedom degree of photographing is reduced.